An Each Way bet is a combined Win and Place bet for your selection to Win and for your selection to come 1st, 2nd or 3rd. Your stake will be halved on the Win and the Place.
If you select the 'Each Way' button, the stake you enter will be doubled.
As you can see below, a $10 stake input will place a bet with $10 on the win at $7.50 and $10 on the place at $1.95.